Kevin Feige has said that Cap 2's "primary storyline takes place post-Avengers, Steve figuring out his place in the world. Tony goes back to Malibu, Thor goes back to Asgard, but there are a number of people who stay in S.H.I.E.L.D. Steve, for the time being, is going to be one of them."

We know that Cap will be a "fish out of water" trying to carve out his own place in the 21st century MCU (Sharon Carter, Falcon, Winter Soldier, HYDRA, Zemo, Arnim Zola and Red Skull could all help with this). But with SHIELD having a big role and the fact that Cap 2 could most directly lead into Avengers 2, it sounds possible that we will see more crossover-related MCU characters in this movie than we will see Iron Man 3 and Thor 2. What non-Cap specific characters/organizations/easter eggs would you like to/expect to see?

I wouldn't mind an easter egg or even cameo from BP, once he gets cast. Cap and T'challa --- or T'chaka, anyway --- have history. Otherwise, I wouldn't really want to see a bunch of non-Cap related characters doing drive-bys.

1: I'd love see Tony Stark be the role his dad played to Rogers
2; something like black panther object or another character reference that will be featured in the third phase like an object
3: Black Widow and Clint ( there not getting a film unless Shield does)
4: Remeber that podcast with Rumors ? Id love see flashback be of Nick Fury And Ross and maybe throw in the commandos since there no way To put them in modern times
5: I'd love see a scene like in Rogers appartment with like a picture of the Avengers in a group photo framed that would be cool.

I say introduce Carol as a Air Force pilot in a cameo ala Hawkeye in Thor. And I'd like to see a team of Black Widow, Hawkeye, and Mockingbird being the first team sent by Fury to encounter Winter Soldier, until Cap is called in, who ends up recruiting Sharon Carter and Falcon himself.
And a cameo of Black Panther would be great as well.

Fury for the obvious reasons.
Hawkeye in a role comparable to Black Widow in Iron Man 2.
Pym just as a background scientist with SHIELD to introduce him into the MCU. Maybe have him work on his new armor or something, similar to Howard Stark in CA:TFA.
Have AIM linked to HYDRA in some way.
T'Challa, like Pym, just to introduce him in the universe. Maybe have AIM/HYDRA going after more Vibranium in Wakanda that was never found, just as a background story to link Iron Man 3, CA:TWS and Thor:TDW together somehow.

Fury and Hawkeye would have large roles.
AIM would have a decent sized role, involved with the Winter Soldier.
Pym and T'Challa would have minor roles.

Traditionally, this foe would have gone to Iron Man, but, Iron Man's slate is full with the Mandarin in IM3, and there is no guarentee we would see an Iron Man 4, and I can't imagine Avengers 2 using a whole movie just for AIM / M.O.D.O.K.

So that leaves Cap 2 and Ant-Man as likely sources for AIM.

But, because HYDRA is more of a concern for Cap, perhaps there would only be a cameo or brief scene involving AIM, while Ant-Man might be able to do the heavy lifting (no pun intended) on bringing AIM to the MCU.

Now that we know the movie will have Winter Soldier, I would really like to see Black Widow, and I would like to see her "betray" SHIELD in a covert mission under Nick Fury's orders. If she does, it would then be cool to see Hawkeye's reaction to that.

This could both serve the plot for CA:TWS as well as serve to help rotate the Avengers roster for TA2 if that is what MS/Whedon wants to do. (If Ant-Man and Wasp join, it might help to have Widow and Hawkeye off elsewhere to keep the roster manageable.)

Now that we know the movie will have Winter Soldier, I would really like to see Black Widow, and I would like to see her "betray" SHIELD in a covert mission under Nick Fury's orders. If she does, it would then be cool to see Hawkeye's reaction to that.

This could both serve the plot for CA:TWS as well as serve to help rotate the Avengers roster for TA2 if that is what MS/Whedon wants to do. (If Ant-Man and Wasp join, it might help to have Widow and Hawkeye off elsewhere to keep the roster manageable.)

I like the idea of Widow betraying SHIELD in favor of personal duty to Fury; and I'm sure Hawkeye is enough of a mercenary to go with her (not to mention he's probably in love with her, too)....

....but I don't see that story line as an excuse to write them out of an Avengers sequel. In fact, just the opposite --- audiences would want resolution to that arc.

I like the idea of Widow betraying SHIELD in favor of personal duty to Fury; and I'm sure Hawkeye is enough of a mercenary to go with her (not to mention he's probably in love with her, too)....

....but I don't see that story line as an excuse to write them out of an Avengers sequel. In fact, just the opposite --- audiences would want resolution to that arc.

Well, I didn't necessarily mean writing them out of the Avengers sequel--they could be occupied elsewhere in the plot, so introducing new members to the team would not force you to have 8-10 people in the room. Widow's secret mission (and Hawkeye in tow) could connect with the main plot and the team eventually. This is kind of like how Star Wars split up the team in ESB and ROTJ, and how X2 handled several threads at the same time.